Electric iron



Aug. 15, 1950 c. H. SPARKLIN 2,518,503

ELECTRIC IRON v 5 Sheets-Sheet 1 Original FiledMay 4, 1945 egg/2 72, W frz z WW- 0 SPARKLIN ELEC Onglnal Filed May 4 945 0 IRON 3 Sheets-s 2 l atented Aug. 1 5, 1950 ELECTRIC IRON Charles H. Sparklin, Chicago, Ill., assignor to Birtman Electric Company, a corporation of Illinois Original application May 4, 1945, Serial No.

591,911. Divided and this application April 24, 1947, Serial No. 743,513 v This invention relates to a heat regulating iron and more particularly to a sadiron in which heat indicating means are provided for indicating the setting of the thermostat at a point remote from the means of adjusting the same.

; This application is a division of my copending application Serial No. 591,911, filed May 4, 1945.

. In my copending application, Serial No. 535,645, filed May 15, 1944, now Patent 2,457,185, dated December 28, 1948, a thermostatic adjustment is positioned in a part of the iron convenient to the fingers with the indicia placed with an indicator in a position on the iron convenient to the eye. This application also includes superimposition of the setting indicator and the temperature indicator so that the operator may ascertain at a single glance how the actual temperature of the iron corresponds to the predetermined setting.

In the present invention 1' have perfected a new iron that provides means for maintaining the finger contacting portion of the heat regulating means in a relatively cool condition. It also provides for sharper control of the temperature by providing a more delicate thermostatic switch. The new iron which is the subject of this invention also has a better balanced construction than that shown by previous irons; it provides for more uniform operating conditions; has cheaper control; and isgenerally greatly superior to any previous iron of the same general type.

The invention will be described in considerable detail as related to the embodiment of the same set out in the accompanying drawings. Of the drawings, Fig. 1 is a side elevation of an iron embodying the feature of this invention; Fig. 2 is a plan view of the iron of Fig. 1; Fig. 3 is a side elevation, partially in section; Fig. 4 is a section taken along line 4-4 of Fig. 3; Fig. 5 is a section taken along line 55 of Fig. 3; Fig. 6 is a section taken along line 6-6 of Fig. 3; and Fig. 7 is a section taken along line 1-4 of Fig. 3. As shown in the drawings, the iron I!) comprises a sole plate H anda hood I2 which togther define the body portion of the iron, 2. handle support 13, a handle l4 containing openings 48 in either side at the rear for positioning of an electric cord, and a control knob IS. The usual form of snap acting thermostat I6 is provided 4 Claims. (CL 219-25) 2 1* plate I I. This thermostat may be adjusted by a movement of the post ll. The thermostatic control includes a make and break switch having contaotpoints 18. One of these points is mount-1 ed on a section of spring steel 19, while the other point is mounted on a short bimetal thermostaticelement 26. This second bimetal element is fastened to another section of spring steel 2!. The second bimetal element 2& provides sharper con-- trol for the switch for when it is heated it curls downward in opposite direction to that of the first bimetal element It. This construction results in a thermostatic switch in which very sharp control is provided.

The thermostatic switch is controlled by rotation of the control knob I5 in the following mane ner. The knob [5 has a central opening in which an internal sleeve 22 is anchored. Within this The square nut 23 is provided at its base with a collar 2! having a groove 28. A broken rocker arm 29 is pivotally mounted in a bracket 30. This rocker arm is engaged at its front end by the sides of the groove 28. The other end of the rocker arm bears against a post 3| that is fastened to the lower spring steel arm H? which carries a contact point [3 for the make and break switch. Thus the post 3| serves to position the switch relative to the first bimetal thermostat element [6. The broken rocker arm 29 is con structed so that it acts as a rocker arm in one direction only. This is provided for by having the rocker arm in two sections, each mounted the first bimetal thermostat element 16 which controls the temperature at which the iron op-" erates, This positioning is accompanied by ro-.

tation of the knob [5. When the knob I5 is ro-j tated,the square nut 23 is moved up or down on the post 26. This moves the collar 21 and thus positions the rocker arm 29 which operates as a in the body of the iron and is afiixed to the sole 5o rocker only when the collar 2! moves upwardly;

When the collar is moved in a downward direction, the rear of the rocker arm is kept in proper position by means of the spring steel section 19 pushing against the rocker arm through post 3|. Such a construction is provided so that the rear portion 33 of the rocker arm may serve as a lever fulcrumed at one end around the rocker arm pivot. It functions as a lever when the free end of the rear portion is pushed down. The purpose of this construction will be explained in greater detail hereinafter.

The Setting of the thermostat is shown by the indicator 34, the end of which points to the indicia 35 mounted below the handle. The end of the indicator 34 appears through an arcuate opening 36 in the body of the iron. In the particular form shown, this opening also passes through the handle support 13, theindicator 3,4 is operated simultaneously with the setting of the thermostatb means of a gear train 3] connected, to the square nut 23. A ring gear 38 havin a square central opening is slidably mountedon the square nut 23 and meshes with the larger circumference of a flat ring reducing gear .39. The smaller circumference of the gear meshes with a toothed areuate member 4.0 attach d 5.0 the mounting! that bears the indicator .34. This mounting 4| is concentric with the Shaft 42 and is designed to turn independently -.of theshaft. The temperature indicator preferably comprises a thermostatic .coil 43 secured to the sole plate H of the iron in a central location. This coil may be a conventional bimetal material n spiral shape adapted to expand and cont act as it'heats and cools. At the inner .end of the coil there is located a post 42 that is rotatable und r the influence of the bimetal coil. The base of the post 42 is rotatably journaled in the'sole plate. As a result when the temperature of the sole plate rises, the coil expands and turns .the shaft. The temperature indicating means :44 is secured to the neck of the shafttZ and rotates therewith. This means comprises a ring 45 having its cir-v cumferential portion underlying the opening .35 and the point of the setting indicator 34. The ring may be painted appropriately, for example, with-a red zone, a yellow zone, and a green zone, and is also marked so that. whenever the yellow zone underlies the temperature setting the :temperature of the iron is the temperature indicated. n the other hand when the red zone underlies the setting indicator, the temperature of the iron will be above that required for a particular operating condition, and when the-greenzoneunder lies the pointer, the temperature of the iron will beibelow-that suitable for the preferred operating conditions. This method of marking and theway in'which the setting indicator andthe-thermometer may be calibrated is explained in detail in my copending application referred to hereinabove.

On the rear section 33 of the broken rocker arm there is mounted an upwardly extending arm 49 carrying at its top aninclined plate i) (Figure 7) The upwardly extending "portion is located so that when the control knob 1'5 is turned to a position corresponding to a high temperature the larger circumference of the ring reducing gear 39 contacts the inclined plate-Stand pushes it down, thereby preventing 'locking of the parts. This serves to push'th-e rear section of the broken rocker .arm down andbreakthe contact of the control switch. It can beiseenithat when the rear portion of the broken rocker arm is-used in the above manner it acts as a *lever 4 fulcrumed at the point of pivot of the broken rocker arm.

After the new iron has been built and before it has been put in operation, it should be synchronized so that the temperature indicator will coincide with the thermostat setting. This can conveniently be done by means of a headless screw 5| positioned in the hub 52 of the temperature indicating means M. The screw presses against post 42 that is attached to the bimetal thermostat 43 after the parts have .been synchronized.

The knob [5 which is used to control the operating temperature of the iron, has a finger contacting portion 46 extending beyond the main body portion of the knob. This extended portion is separated from the rest of the knob by deep circular grooves 47 on either side which serve to keep 1 h? finger contacting portions 66 cool.

The broken rocker arm 29 and its function are shown and described and claimed in my copend- 'ing application Serial No. 700,957, filed October The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitation should be understood theref om.

. In an e ec ric ron hav n a bod p t o and an e ectr hea i e emen t r c v b at therefrom. a metal the mostat el m n the ody adja nt t heatin e ement. w tch the electr a c rcui tosaid h atin element and said heating element when heated and said .seea 1 d hlmetal element curling toward said heating element when heated by electricityxpassingthere= through to increase the speed of separation ,of said contact members when the bimetal elements are subjected to heat.

.2. The electric iron of claim 1 wherein one of said contact members is mountedon said-second bimetal thermostat element. 7

3. In an electric iron having a body portionand an electric heating element, a bimetal ther-' mostat element havingone-end mounted in close proximity with the heatingelement-and the other end arranged to curl away from the heating element under the influences of heat, a mounting" member spaced from said 'bimeta'l, a contact arm having one end held iii-said mounting member,

a contact member onthe other end of said armfl and arranged on the side thereof opposite said bimetal, a second mounting member located on the side of said first mounting member that is o p'- posite-said bimetal, a flexible contact arm having one end held in said second mounting member and arranged alongside said first contact arm, a" second bimetal thermostat element having one end attached-tothe other end ofsa'id flexible contactarm and the other end of the second bimetalextending beyond the corresponding end of said first contact arm,;said second'bimetalhaving saidother end arranged to curl toward the first contact arm and said first bimetalunder the influence of heat, a cont-actmember mounted on said second bimetal and intermediate the ends thereof for cooperative contact with said first contact member, said contact members being arranged in the electrical circuit to said heating element, and a post member mounted on the outer end of one of said bimetal elements and bearing against the outer end of the other bimetal element for causing relative movement of said bimetal elements away from each other and separation of said contact members when said bimetal elements are subjected to heat.

4. In an electric iron having a body portion and an electric heating element, a bimetal thermostat element in the body adjacent the heating element, a switch in the electrical circuit to said heating element and including a, pair of cooperating contact members, a pair of arms each carrying a contact member, a second bimetal thermostat element forming a part of one of said arms, and a linkage means between said first bimetal thermostat element and one of said arms for causing separation of said contact members at a predetermined temperature, said bimetal thermostat elements serving to increase the speed of separation of said contact members when the bimetal elements are subjected to heat, one of said contact members being mounted on said second bimetal thermostat element at a point 6 spaced inwardly from the outer end of said element, and said linkage means being attached to said second bimetal thermostat element at a point adjacent said outer end, both said bimetal thermostat elements being arranged to curl inwardly toward each other under the influence of heat.

CHARLES H. SPARKLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,606,037 Myers Nov. 9, 1926 1,962,587 Getchell June 12, 1934 2,127,083 Howe Aug. 16, 1938 2,235,479 Gough Mar. 18, 1941 2,270,736 Kuhn et al Jan. 20, 1942 2,353,151 Eisenheimer July 11, 194-1 2,403,115 Olving July 2, 1946 2,422,526 Burch June 17, 1947 2,427,945 Clark et al Sept. 23, 1947 FOREIGN PATENTS Number Country Date 558,735 Great Britain Jan. 18, 1944 Certificate of Correction Patent No. 2,518,503 August 15, 1950 CHARLES H. SPARKLIN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, lines 29 and 30, strike out the Words to receive heat therefrom and insert the same in line 31, after element and before the comma;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of December, A. D. 1950.

THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents.

Certificate of Correction Patent No. 2,518,503 August 15, 1950 CHARLES H. SPARKLIN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows;

Column 4, lines 29 and 30, strike out the Words fto receive heat-therefrom and insert the same in line 31, after element? and before the comma; and that the said Letters Patent should be read es corrected above, so that the same may conform to the recor of the case in the" Patent Ofiice.

Signed and sealed this 5t daynof December, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

